PHOENIX—Gregory Lynn Shrader, 55, of Jay, Okla., was found guilty of willfully making a threat to kill by means of an explosive, transport of explosive material with the intent to intimidate, mailing injurious articles, and possession of explosive material by a prohibited possessor, by a federal jury in Phoenix. The case was tried before U.S. District Judge Neil V. Wake between Sept. 4, 2014 and Sept. 11, 2014. The defendant is being held after trial. Sentencing is set before Judge Wake on Dec. 1, 2014.

The evidence at trial showed that Shrader threatened to kill Sheriff Joe Arpaio with an improvised explosive device on April 10, 2013. The evidence at trial showed that Shrader made the mail bomb threat as part of a revenge scheme to frame a former business partner. Sometime in early 2013, Shrader constructed an explosive device and placed it into a United States Postal Express Mail Box and designed it to appear operational.

The evidence at trial showed that Shrader was unhappy with the results of two failed lawsuits filed against his former business partner. As an act of revenge, Shrader addressed his package to Sheriff Joe Arpaio with a return address belonging to his former business partner.

A conviction for willfully making a threat to kill by means of an explosive carries a maximum penalty of 10 years, a $250,000 fine or both. A conviction for transport of explosive material with the intent to intimidate carries a maximum penalty of 10 years, a $250,000 fine or both. A conviction for mailing injurious article carries a maximum penalty of one year, a $100,000 fine or both. A conviction for possession of explosive material by a prohibited possessor carries a maximum penalty of 10 years, a $250,000 fine or both. In determining an actual sentence, Judge Wake will consult the U.S. Sentencing Guidelines, which provide appropriate sentencing ranges. The Judge, however, is not bound by those guidelines in determining a sentence.

The investigation in this case was conducted by the United States Postal Inspection Service and the Federal Bureau of Investigation. The prosecution was handled by Assistant United States Attorneys Raymond K. Woo and Paul Stearns, District of Arizona, Phoenix.